Mud pump refers to the machinery that delivers mud or water and other washing liquid to the drilling hole during the drilling process. Mud pump is an important part of drilling equipment. In the commonly used positive circulation drilling, it is the surface flushing medium - water, mud or polymer flushing liquid under a certain pressure, through the high-pressure hose, faucet and drill pipe string center hole directly to the bottom of the drill, in order to cool the drill bit, cut down the cuttings removed and transported to the surface of the purpose. The commonly used mud pump is a piston or plunger type, which is driven by the power engine to rotate the crankshaft of the pump, and the crankshaft drives the piston or plunger through the cross head to do reciprocating movement in the pump cylinder. Under the alternating action of suction and discharge valves, the purpose of pressing and circulating flushing liquid is realized.